<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        .parent{
            display: flex;

            justify-content: space-evenly;
            width:550px;
            height:380px;
            background-color: darkblue;
        }
        .item{
            width:100px;
            height:100px;
            background-color: darkgoldenrod;
        }
        .parent .item:nth-child(5){
            background-color: red;
            /*order的默认值是0*/
            order:-1;
        }
        .parent .item:nth-child(1){
            background-color: #004b00;
            /*order的默认值是0*/
            order:1;
        }
    </style>
</head>
<body>
<div class="parent">
    <div class="item">1</div>
    <div class="item">2</div>
    <div class="item">3</div>
    <div class="item">4</div>
    <div class="item">5</div>


</div>
</body>
</html>